I have a 97 F-150 SuperCab with 220,000+ miles on it.

I can't say enough good things about this vehicle. The truck is completely original except for brakes, shocks, front suspension components, filters, fluids and the alternator which finally bit the dust at 213,000.

I have owned 3 previous Ford trucks, 75 F-250, (32,000), 77 F-250, (220,000) and an 86 F-250 Diesel (251,000). This by far has been the best vehicle I have owned.

Have two challenges though. 1. The brakes. After the second brake job by an independent shop, I began to get a rhythmic surge when doing a slow controlled stop at around 10,000 miles on the brake job. High ambient temperatures seem to add to the problem. Took it back to the same shop, (Who has done work for me for 20 years), and paid for a new front brake job. At around 10,000 miles the surge returned. Also during a high speed deceleration, as when exiting an interstate from cruise speeds, the brakes give a rapid 'cycling' sensation, almost as if the rotors are grabbing.

2. An apparent drive train vibration. This minor vibration occurring between 59 and 63 mph started around 175,000 miles. The tires at the time were near the end of their service life so I had another set of Michelins installed and balanced. The vibration persisted so I took it to the local Ford dealer near my home in Houston. They changed both universal joints. I took the truck out to my favorite stretch of level, smooth and quiet road for a test, and the vibration was still there. Took the truck back to NTB where I bought the tires and had them recheck the balance. They did without question and showed me that there was no problem with the tires or balance. I was out of time so I did not return to the Ford dealer near my home. A few months later, as the vibration was increasing in intensity but still between 59 and 63 mph, I took the truck to a Ford dealer in North Richland Hills, Texas. They determined that the ring and pinion gear needed to be replaced, as well as one of the universal joints that the previous Ford dealer had installed incorrectly, and all the rear wheel and differential bearings. Almost $1,400.00 later, as I left the dealer and tested the truck on a smooth quiet stretch of road, the vibration is still there and is continuing to increase in intensity. As I have thought about this over an extended period of time, I have noticed that my transmission has had a minor seepage since I had it in for annual Transmission service early in 2002. Never enough to spot the driveway or parking lot, but enough to notice everytime I change oil. Is there any chance that there is a bearing in the rear of the transmission that could be failing?

In over 500,000 miles of driving Ford Pick-Ups, I've never had a transmission or rear-end problem.

Anyone have any thoughts or ideas?

Thanks,

Ron

 

Hi Ron and welcome to FTE
Your brake pulsation is probably caused by either warped drums or rotors or both. Usually if it is the fronts that are warped the steering wheel will usually shake along with the brakes. If it's the rears you'll feel it more in the seat than the steering wheel. When the brake job was done did they replace the rotors?
If not you might want to replace them or try turning (resurfacing) them. If they were replaced you should probably turn them.
Vibrations can be very hard to diagnose with the truck there, even harder trying to do it on here. Is the vibration a higher speed vibration or more like a shimmy? Do you feel it in the steering wheel or seat? Any noise to go with it?

 

Re: drive line vibration----has truck ever been wrecked? is it 2wd or 4wd? from your email it sounds as though you have isolated the vibration as coming from the rear end. But if you arent sure, you may need front wheel bearings and/or a set of shocks all around. When the vibration is at its worst (around 60mph or so) note your tach rpm speed. then downshift and bring the engine speed to the same rpm. if the vibration occurs at the same engine speed no matter what gear the tranny is in, the driveshaft is not at fault. if vibration calms down or stops when tranny is in different gear but at the same engine speed, it might be 1) bent driveshaft 2) dirt or whatever clinging to the side of the driveshaft to make it run out of round 3) driveshaft out of balance. any weights missing on the driveshaft? if not, pull the driveshaft and reinstall 180 degreees from original position. if all else checks out, are your motor mounts ok. good luck, let us know what you find.

 

Thanks for your rapid response and advice, Dave.

I have the drums and rotors machined everytime I have the shoes and caliper pads replaced. ( 77,000, 155,300, and 182,000 on the front again) I do get a vibration, or side to side movement of varying degree in the steering wheel at the very end of the braking cycle, much like when a pitman arm is worn. The problem appears to return about 10,000 miles after the drums and rotors have been resurfaced. As I thought about your comments, I remembered that when I first moved to Houston, there was significant flooding from Tropical Storm Allison and I drove through water that was almost hub deep. My question is, if a drum or rotor was warped beyond salvage, wouldn't the symptoms remain constant even after machining? Could 'aftermarket' caliper pads be causing the problem? (as opposed to Ford parts from the dealer)

I never detect any noise when braking.

On another note,... I'm impressed with this website. Keep up the good work. Ron

 

03f150man,

Thanks for your suggestions. It will be a few days before I can get out to road test them, but will be back in touch.

Ron

 

If you've had the drums and rotors turned a few times now they are probably getting thin and will warp easier than new ones would. Quite often warped drums and rotors dont feel too bad until the brakes are hot. If the brakes were hot when you went through the water that can sometimes warp them too.
Aftermarket pads are usually ok and shouldnt cause problems.
Some cheap aftermarket drums and rotors arent very good and warp easily.

 

For 03F150Man:

OK, I have finally had a chance to check out your suggestions. First, to answer your original questions, the truck is a 97 Supercab with a 4.6 V8 and Overdrive transmission. Never wrecked, shocks have been replaced about every 22,00 miles. Front bearings are relatively new as are the rear wheel bearings and the differential bearings.

The vibration/noise starts at 1,800 RPM, (58 MPH) when in overdrive and remains until about 63 MPH or just over 2,000 RPM.

I disengaged the overdrive and tracked it on a smooth newly surfaced roadbed. In 3rd gear, the vibration starts about 2,800 RPM, still at roughly 58/59 MPH. I noted that he vibration has a different frequency at 2,800. Any new thoughts?

 

This is a wild hair but maybe you have a bad bushing in your steering components, it happened to me on an older model of ford 91. I would hit a speed of 35 or so and it would vibrate my teeth out of my scull. And it was a bad bushing from the pitman arm down. Or so in new models the idler arm. An easy way to tell if it is a bad bushing is have two people while parked just turn your tires back and forth and see if your body jumps or moves while your tires turn.

 

Take the "driveshaft" out and have it "balanced".
I did with mine and it is smooth now.

 

RF6004, I am having the same problem with a 2000 F-150, 49K miles, between 56 and 62 MPH, around 1700 RPM in overdrive. My Ford dealer has replaced the rear ehxaust dampner ($290) no help, then they replaced the rear differential ring and pinion and other rear end stuff ($1400 of their money), and I still have the same problem you have described. Now Ford wants to go after the front differential and rebuild it, at my cost of course. The truck runs great in all other speeds and gets great gas mileage. Just bought it 6 weeks ago.

 

For Hutch99,

Thanks for the information, its heartwarming to know I'm not the only one with a problem like this. I talked wth a Service Writer at another Ford dealership this past weekend, (not the same one that replaced my Ring & pinion), and he suggested that it could be the torque converter, (another $1,400 item). I think I'm going to take Omega Man's suggestion and rebalance the driveshaft first. I guess ts possible that drive-through car wash facilities that have an underbody pressure wash could have knocked a weight off.

 

For RF6004, I would have thought that Ford in both our cases would have thought to check for an out of balance drive shaft. This weekend I will check the fluid level in the front differential and take a look at the drive shaft for any apparent loss of balance weights. Good luck, and I will try and keep in touch on this one.

 

The driveshaft must be balanced on a lathe type tool to find out if it is balanced or not

 

Ron (RF6004),

Any final word on the driveshaft being out of balance? The seal at the tranny sounded like a smoking gun, and the fact that it seems to be tied to your road-speed rather than your RPM points to something aft of the transmission...

Starting to notice a similar problem with my '97 and monitoring closely...

Regards,
Bryan ("Chum")

 

Hi Chum and welcome to the forum
Have you checked out your U-joints, tire balance etc yet?
If you snoop around in the forum here you'll find quite a few posts about similar problems with some good ideas on how to fix it.